[tdw]

Well, it happened again. It was fine until I'd used it to make a coffee this morning, then it started dripping again.

It's not like there's a steady stream of water so it's a bit hard to tell which hose it's coming from as there's no obvious steady flow, but by process of elimination it looks like it's the one circled in red below. The other two have bubbles in them that aren't moving, so I assume there's no flow of water in them. The 'red' hose has a little bubble down towards the blue plastic union that is bobbing up and down in time with the drips.

Now the potentially interesting part. I decided to turn on the steam boiler once I noticed it'd started dripping again. As the steam boiler was warming up, there was a steady, continuous flow of water out of the circled hose above and out of the nipple. Like, a-jet-of-water continuous. This lasted about 20s then stopped. Once the steam boiler was up to temperature things seemed to stabilise and the machine behaved normally while I made coffees and pulled some blind shots.

Finally, as a bit of an experiment, I turned the steam boiler off again. After doing so I thought I'd empty some of the water out of it using the tap, thinking that if it's a problem with the refilling of the boiler then if I left it with a lower level of water, it should take longer for the problem to re-occur, or I should see more water disappearing from the tank (??). Also potentially of note, opening the tap was incredibly steamy and 'spat' a lot. (Is it meant to do that?)

 

[MediumRoastSteam]

It's the vacuum breaker valve. So that's not shutting properly and your boiler is most likely overfilling.

What water are you using?

 

[MediumRoastSteam]

What you could do is to remove the hose from that nozzle.

Proceed to warning up your machine as normal, with the service boiler turned off.

Put a cloth around it to collect any water. Or, disconnect the other end of the hose and divert it to cup or something.

If water starts coming out of it, when is that happening? How hot is the brew boiler?

Is it a lot of water coming out? Is it spluttering?

If the service boiler is off, and the water is not spluttering (it shouldn't) then you have a problem with your fill sensor. You can take it off , give it a good clean, put it back and see if it happens again.

If water keeps coming out at a steady rate, the pump should kick in at some point to refil the boiler. Is it doing that?

 

[tdw]

Thanks. I did think about pulling the hose off as a troubleshooting measure but it's on there pretty tight and as everything was hot I didn't fancy it. I've only ever used Volvic in this machine, to the dismay of my wallet(!). The pump does seem to run to refill the boiler as the water is coming out of it at the faster rates. I haven't noticed it when it's just dripping slowly but I haven't exactly stood around waiting for it.

Is there a wiring diagram for these things so I can see what's what?

 

[DavecUK]

The problem is an overfilling service boiler, solve that problem. Vac breaker is most likely fine.

Check combined thermostat and fill sensor to left of circled area. It has red and white wire attached, you problem is most likely there. Might try replacing it, if you think the pump is running for an overly long time on boiler filling.

Otherwise could be a badly sealing auto fill solenoid.

 

[Rob1]

Thanks. I did think about pulling the hose off as a troubleshooting measure but it's on there pretty tight and as everything was hot I didn't fancy it. I've only ever used Volvic in this machine, to the dismay of my wallet(!). The pump does seem to run to refill the boiler as the water is coming out of it at the faster rates. I haven't noticed it when it's just dripping slowly but I haven't exactly stood around waiting for it.

Is there a wiring diagram for these things so I can see what's what?

Volvic scales and pretty much anything you put into your machine will scale in a service boiler eventually unless it has no minerals at all (just bicarbonates). If it isn't scaled up the other things to check have been outlined.

 

[MediumRoastSteam]

Dave is right as usual. You vaccum breaker is most likely fine. When I say "it's not shutting properly", I meant "it's not shutting" because the service boiler is not up to temperature (as it's switched off) and therefore the valve remains open. If nothing is coming out when the boiler is on and up to temp as you described, then, as Dave says, it's most likely fine.

 

[MediumRoastSteam]

So we went through all of this but I never asked... is this machine still under warranty? Where did you buy it from?

 

[tdw]

I've only had it for a month so surely it can't be scaled up already!

It came from BB so it's all under warranty. I was just going to try to sort it myself if it was something obvious, since it's a bit hard to get the machine up to them right now.

Dave's explanation makes sense, thanks.

 

[MediumRoastSteam]

I've only had it for a month so surely it can't be scaled up already!

It came from BB so it's all under warranty. I was just going to try to sort it myself if it was something obvious, since it's a bit hard to get the machine up to them right now.

Dave's explanation makes sense, thanks.

Give them a ring. Explain to them your findings. They should at least try to help you diagnose and guide you through fitting a new probe if that's what it needs. Theirs service is excellent.

Good luck!

 

[Rob1]

I've only had it for a month so surely it can't be scaled up already!

It came from BB so it's all under warranty. I was just going to try to sort it myself if it was something obvious, since it's a bit hard to get the machine up to them right now.

Dave's explanation makes sense, thanks.

It depends on usage.

You've pulled shots and ran the pump against a blind filter and noticed the leaking hasn't got worse or has stopped so the solenoid is at least shutting properly. That really just leaves the autofill probe to check...

 

[tdw]

One other question while I'm here. Is the service boiler supposed to fill under normal operation, when the machine has the service boiler turned off? Or should it only fill if enabled?

 

[MediumRoastSteam]

As far as I know, it should always fill regardless whether the element is enabled or disabled.

 

[tdw]

Thanks. I've run the machine with the service boiler on for the last couple of days and it seems to be behaving itself. Have contacted BB anyway.

 

[TonyCoffeeNewbie]

Thanks tdw this thread has helped me with a repair...

Just giving the bianca its first annual check this morning and found the connector between the silicon pipe and the service boiler anti vac valve had failed, see first pic below. The connector was an ulka part identical to that on the expansion valve. on removing the connector it simply crumbled into pieces, most likely due to heat cycles. So as a quick fix I cleaned up and connected the silicon hose directly onto the anti vac valve with the intent of replacing the connector later.
On looking at the images of your machine it looks like the pipes connect directly anyway. So my temporary fix will now be more permanent.

This does show the slight variations in the build of machines. I suspect others may have the same problem as me.

Tony

Sent from my SM-G973F using Tapatalk

 

[DavecUK]

i'd leave the fix like that, IMO better than that angled connector.

 

[tdw]

Glad something useful came out of this!

As usual BB service was great. I didn't want to ship the thing so I drove it up there and they managed to fix my machine while I waited.

 

[jakery]

Hi @tdw - What was the final resolution here?

My Bianca is suffering from the same sputtering, steamy leaks from the same hose that you identified here:

https://www.coffeeforums.co.uk/topic/52011-dripping-bianca/?do=embed&comment=744345&embedComment=744345&embedDo=findComment

How did you end up fixing this?

 

[MediumRoastSteam]

Hi @tdw - What was the final resolution here?

My Bianca is suffering from the same sputtering, steamy leaks from the same hose that you identified here:

https://www.coffeeforums.co.uk/topic/52011-dripping-bianca/?do=embed&comment=744345&embedComment=744345&embedDo=findComment

How did you end up fixing this?

That's the vacuum breaker. Could you please define "steady leaks"? When does it happen? Is it during warm up or when using the machine? How did you notice it was leaking?

(Ps: welcome to the forum).

 

[jakery]

Hi @MediumRoastSteam - Thanks for the welcome.

Here's a video of my vacuum breaker valve leaking:



It leaks constantly after the machine has warmed up, a steady belching of steam and spurts of droplets.

I noticed that it was leaking months ago but did not realize that this was not normal until my neighbor saw it and flagged to me that there might be a problem. 🙃

The machine is 1 year old.

I disassembled the vacuum valve hoping that there was scale I could clean for an easy fix. I did find a bit of debris in there but nothing major. Even after cleaning it's still sputtering steam. I suspect that the o-ring has failed. It was hard and a bit misshapen.